1. Field of the Invention
This invention relates to a cutting means and more particularly to a cutting means adapted to sever materials by means of a crushing action. Specifically, the instant invention relates to a cutting means employing two heated eccentrically mounted rollers adapted to coact with each other in order to sever a material by means of a crushing action and which is particularly adapted to cut the innerliner material used in the fabrication of tires from a continuous length of innerliner material.
2. Description of the Prior Art
The use of cylindrically shaped members to cut materials from a continuous length of material is well known as evidenced by U.S. Pat. No. 2,420,525 to DeLoye and U.S. Pat. No. 3,448,594 to Macon. In general, this art discloses the use of rollers to effect separation of a substantially continuous material at regular weakened portions thereof by causing stresses at the weakened portions which result in separation of the material at the weakened portions.
Apparatus utilized to produce weakened portions or serrations in a substantially continuous length of material are well known in the art as evidenced by U.S. Pat. No. 3,214,502 to Schaar, U.S. Pat. No. 3,570,337 to Hogan, U.S. Pat. No. 4,009,237 to Kimura, et al., and U.S. Pat. No. 4,181,070 to Robbins, et al. This art generally discloses a rotary means for scoring or causing a partial separation in a continuous length of material wherein said continuous length of material may in a subsequent operation be severed or separated at the scores or serrations to produce the desired length of the material.
Transfer machinery adapted to transfer a substantially continuous length of material for performing operations thereon is well known in the art as evidenced by U.S. Pat. No. 4,151,038 to Bottasso, et al., which discloses the use of linearly movable fingers to impart motion to a continuous length of material.
The use of a rotary die to cut a continuous length of material is disclosed in U.S. Pat. No. 3,905,283 to Baker.
Although the above-noted prior art discloses several methods for cutting continuous lengths of material, the method employed in the fabrication of a tire differs substantially from them. Specifically, the tire industry typically employs a tire assembly machine having a tire building drum to which the various components of a tire are manually applied by an operator. A gum strip is first applied laterally across the tire building drum. The first edge of the air impervious innerliner is then applied to the gum strip on the tire building drum such that the first edge of the innerliner material is located approximately in the middle of the gum strip. The tire building drum is then caused to be rotated by the operator, which rotating motion causes the innerliner material to be drawn from a material server adjacent to the tire building drum. When the tire building drum has completed one revolution, the rotary motion of the tire building drum is stopped. The operator then manually determines the point at which the continuous length of innerliner material must be cut in order to provide a small overlap of the innerliner material with the first edge of the innerliner material and then subsequently cuts the innerliner material with either a knife or a scissors. The ends of the innerliner material are then manually stitched and the remainder of the materials are applied to the tire building drum over the innerliner material by the operator.
It should be noted that it is necessary to apply the gum strip to the inner joint between the two ends of the innerliner material in order to prevent subsequent contamination of the joint between the two ends of the innerliner material by release compounds applied to the inside of the tire prior to vulcanization of the tire. It has been found that contamination of the joint between the two ends of the innerliner material by release compounds applied prior to vulcanization may result in incomplete bonding between the ends of the innerliner material with subsequent separation of the innerliner ends which results in cracking and failure of the innerliner material and subsequently tire failure.
The manual application of the gum strip to the tire building drum by the operator increases the amount of time required to make a tire and necessitates the stocking of the gum strips thereby increasing the cost required to make a tire. In addition, the use of the gum strip requires the stocking of the special gum strip material which increases the manufacturing cost of the tire. Further, the gum strip material is incompatible with the other components of the tire due to its formulation. Therefore, should gum strip material be mixed with other components of the tire, there is a high probability of tire failure. Elimination of the use of the gum strip thus represents an improvement in the quality of the tires manufactured. Even further, the use of an additional component, namely the gum strip, also provides an additional area for manufacturing error which would be eliminated by eliminating the use of the gum strip.
There is, therefore, a need for a means for automatically cutting a continuous strip of innerliner material to the correct length for application to a tire building drum to thereby eliminate a manual cutting operation required of the operator with the advantage of increasing production and reducing operator fatigue. There is also a need for a means for joining the two ends of the innerliner material without using a gum strip on the joint thereof.
The instant invention solves these problems by providing a means of automatically cutting from a continuous length of innerliner material, a portion of the exact length required in fabricating a tire and even further cuts the innerliner material in such a manner as to allow the joining of the ends of the cut piece of innerliner material without having to use a gum strip on the joint between the ends of the innerliner material.